“Underlying all this activity—in the customhouses, on the wharves, in every place of business—were numbers. Merchants measured out their wares and negotiated prices; customs officers calculated taxes to be levied on imports; scribes and stewards prepared ships’ manifests, recording the… — Keith J. Devlin Copy Share Image
“When he was about fourteen years of age, Leonardo would have left the fondaco and most likely traveled with an older merchant, a form… — Keith J. Devlin Copy Share Image
“a baby’s failure to reach for an object hidden under a blanket does not support the rather dramatic conclusion that the baby thinks the… — Keith J. Devlin Copy Share Image
“Having described the basic methods of Hindu-Arabic arithmetic in the first seven chapters, Leonardo devoted most of the remainder of the book to practical… — Keith J. Devlin Copy Share Image
“In chapter 10, he explained how to use similar methods to manage investments and profits of companies and their members, and showed how to… — Keith J. Devlin Copy Share Image
“By the latter part of the first millennium of the Current Era, the system we use today to write numbers and do arithmetic had… — Keith J. Devlin Copy Share Image
“A significant difference between Pacioli’s book and Treviso Arithmetic is that Pacioli dealt with negative numbers. The concept of negative numbers was new in… — Keith J. Devlin Copy Share Image
“a mathematician is someone for whom mathematics is a soap opera.” — Keith J. Devlin Copy Share Image
“The choice of ten basic number symbols—that is, the Hindus’ choice of the base 10 for counting and doing arithmetic—is presumably a direct consequence… — Keith J. Devlin Copy Share Image
“The number system we use today—the Hindu-Arabic system—was developed in India and seems to have been completed by around 700 CE. Indian mathematicians made… — Keith J. Devlin Copy Share Image
“Underlying all this activity—in the customhouses, on the wharves, in every place of business—were numbers. Merchants measured out their wares and negotiated prices; customs… — Keith J. Devlin Copy Share Image
“European scholars had translated into Latin two important Arabic manuscripts, written by the ninth-century Persian mathematician Abū ‘Abdallāh Muammad ibn Mūsā al-Khwārizmī (ca. 780–ca.… — Keith J. Devlin Copy Share Image
